The present invention relates to a fluid control device used in, for example, a semiconductor manufacturing apparatus, specifically to a fluid control device in which two different types of fluids can be selectively introduced and discharged.
According to the industrial needs, some fluid control devices used in semiconductor manufacturing apparatuses are configured to supply two different types of gases to a treatment chamber. Patent Literature 1 (Japanese Patent Application Laid-Open No. 2004-214622) discloses an example of such a fluid control device in which two different types of fluids can be selectively introduced and discharged. The fluid control device disclosed in Patent Literature 1 has a cylindrical body (head assembly) and two opening and closing valves fitted to the body, wherein the body is attachable to an opening provided in a capping member of a treatment chamber.
The two opening and closing valves of the fluid control device are fitted to the body facing each other in parallel so that the two fluids introduced to the opening and closing valves are swirled around in the body to be mixed with each other and then transmitted to the chamber.
According to the conventional fluid control device, the two fluids (gases) swirled around in the body are often retained. Depending on types of the introduced fluids, a reaction may be generated between the fluids mixed with each other, and a reaction product thereby generated near a discharge port extending from the fluid control device invites the problem that inside of the chamber is contaminated with resulting impurities.